Geothermal bill would establish research sites / System using heat from ground to create electricity to be studied

Ralph Hermansson, Chronicle Staff Writer

Published 4:00 am, Monday, June 18, 2007

With oil and natural gas prices soaring, the world seems to be searching for the next great source of energy. And while most people are looking to the heavens -- tapping solar and wind resources -- the answer may lie in the ground beneath our feet.

This subterranean source is known as geothermal energy and it's already being used to heat homes. Now, some lawmakers are pushing for an increase in research and development into the technology.

U.S. Rep. Jerry McNerney, D-Pleasanton, is sponsoring a bill that would support the development of this source of power that some people believe can eventually supply electricity to 75 million homes. And if McNerney succeeds, one of the research and development centers created to nurture geothermal energy might be located in Northern California.

The bill, the Advanced Geothermal Energy Research and Development Act of 2007, unanimously passed the House Committee on Science and Technology last week. Its aim is to develop enhanced geothermal energy, using the heat from the ground to create electricity.

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Here's how it works: Using a closed system, cool water is pumped into hot, fractured rock reservoirs deep beneath the ground where the water is heated. The steam is pumped back to the surface to a turbine that is attached to a generator and produces electricity.

Some people already use a scaled-down version of this technique to heat their houses, but McNerney's proposal would create geothermal power on a much bigger scale. Instead of tapping heat out of a 200-foot hole in the ground, which is the way it is done for single-home heating systems, geothermal power plants would have holes more than 30,000 feet deep, using underground man-made reservoirs to house the water.

The Massachusetts Institute of Technology estimates that such a system could provide more than 100 gigawatts of energy over the next 50 years, supporting 25 million of homes with power.

But that's still a way off. McNerney's bill would authorize $90 million a year between 2008 and 2012 to support geothermal research at two centers, one in the West and the other in the East.

"There's definitely a chance that one of the plants would be located in Northern California," McNerney said. "It's important that the rocks are suitable for this. They must have fissures and cracks so you can circulate water through them."

Jeff Tester, a professor of chemical engineering at the Massachusetts Institute of Technology, agrees. "There's a high probability for a research center in Northern California" he said. "One reason is that the demand for the energy that is created is relatively close by."

Tester said that, unlike other environmentally friendly sources, geothermal energy does not depend on wind or sunshine. This system can provide an uninterrupted supply of electricity, day or night.

"This is definitely one of the arsenal of tools that will be needed in the future. I think we will need both solar, wind and geothermal energy," Tester said.

The bill has so far had bipartisan support and not caused any controversy. Most politicians seem to agree that alternative energy systems that can help reduce greenhouse gases are worth supporting.

That's why McNerney is optimistic about the future of the bill.

"It may be wrapped up in a bill with other energy-related questions, but I think it could be signed by the president before the end of this year," he said.

Karen Wayland, legislative director at the National Resources Defense Council, said McNerney's estimate is optimistic. "But I think the bill has pretty good chances," she said. "It will probably be part of the energy package that Speaker (Nancy) Pelosi will bring to the floor in July."

Her group supports the increased use of geothermal energy.

"Our only concern is that it doesn't alter the geography of places like Yellowstone (National Park)," she said. "Proper protection and adequate safeguards are always needed."